Refrigerating apparatus



Feb. 8, 1938. F. R. ERBACH REFRIGERATING APPARATUS Filed Sept. 2l, 19325 Sheets-Sheet l 23a l t INVENTOR.

F'Reomem( I@ Eleam A TTORNEY.

Feb. 8, 1938.A F R- ERBACH y 2,107,630 I REFRIGERATING APPARATUS Filedsept. 21, 1932 5 Sheets-Sheet 5 4H4 l I-----' l 251 //5 i 7z I 1 7, g 1

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Feb. 8, 1938. F* R ERBACH 2,107,630

REFRIGERATING APPARATUS Filed Sept. 2l, '1932 5 Sheets-Sheet 4 l IZ . 45INVENTOIL F 7. 7. el 60 Ptsoeglclc R- RIMM ATTORNEY.

Feb. s, 193s. F R ERBACH 2,107,630

REFRIG ERAT ING APPARATUS //5\ 4l F 5' INVENTOR.

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Petenied Feb. s, 193s PATENT OFFICE 2,107,630 l REFRTGERATING APPARATUSFrederick n. Erbach, Beloit, wie., assigner, by

mesne assignments, to Nash-Kelvlnator Corporation, Detroit, Mich., acorporation of Maryland Application September 21, 1932, Serial No.634,129 1 claim. (ci. 23o- 139) A `further object is the provision of asimple and effective device for permitting the driving motor tosubstantially reach'its ,normal operate ing speed before any materialload is placed on it.

Still another object of the invention is to provide a compressor of thependulum rotary type having a radial abutment member rigidly attachedthereto, which abutment member reciprocates between two oscillatingmembers during the operation'of the compressor, the relationandoperation of the parts and their coordination being such that acompressor of high eiliciency for gas compressing purposes is provided.

My invention also includes improved intake and discharge valvestructures particularly designed for use` with a compressor of the typebefore mentioned.y

By this invention there is valso provided an improved lubricating systemfor an enclosed motorcompressor unit in which the lubricating medium ispositively circulated through the -moving parts of the mechanism,circulated outside the enclosing casing and then cooled, and thenreturned to the casing in its "cooled state to assist in removing theheat generated by the motor and compressor during their operation.

Other objects and advantages of the invention will be apparent from thefollowing description and accompanying drawings wherein:

Fig. 1 is a vertical view, partly in section, of a refrigerator cabinetshowing my improved refrigerating mechanism in operating relationthereto. i

Fig. 2 is a 4vertical view partly in section through the-compressionmechanism taken on the line II--II of Fig. 3 and showingdiagrammatically its relation to the other parts of the refrigeratingsystem.`

Flg. 3 is a vertical view partly in section of the compression mechanismand taken at a displacement of substantially 90 from the view in Figure2.

Fig. 4 is a vertical sectional view on an en larged scale of thecompressor proper, taken on the line IV-IV ofrFlg. 8.

Fig. 5 is a detailed view partly in section showing the connection ofthe oil return conduit to the compressor housing.

Fig. 6 is a plan view partly in section, taken von the line VI--VI ofFig. 3 and showing dctails of the compressor base and oil pump.

Fig. 7 is a fragmentary vertical sectional view taken on the lineVII-VII of Figure 6 and showing further details of the oil pump andlubrication features.

Fig. 8 is a plan view partly in section of the compressor per se.

Fig. 9 is an enlarged vertical section taken on the line IX-IX of Figure6 and showing details of the inlet and discharge valve mechanisms forthe compressor.

Figs. l0, 11, 12, and 13 are detail views o1' component parts of thedischarge valve mechanism, and i Flg.`14 is a vertical view, partly insection, and showing a preferred structure for making an electricalconnection through the casing to the enclosed motor. l

Referring to the drawings wherein is shown a specic embodiment of theinvention, I0 designates a refrigerator cabinet supported by legs I2 andprovided with insulated walls II which together with a swinginginsulated ydoor I3 form a food storage compartment I4. The refrigeratingapparatus comprises generally a heat insulated base I5 which isremovably supported, as by members I6 and thus forms a removable topwall for the food storage compartment I4. A heat-absorbing unit I1 isilxedly secured lto and suspended from the base I5 within the foodcompartment. The heat-absorbing unit may be of any suitable constructionbut is here shown as a sheet-metal evaporator of the type described andclaimed in the co-pending application of Ransom H. Beman, Serial No.556,420 filed Aug. 11, 1931, and assigned to lKelvinator Corporation.

Mounted on the upper side of the base I5 and llocated within a machinecompartment lI8 formed. integrally with the cabinet above the tachedthereto may be bodily removed from the cabinet in a vertical direction.

mechanism is shown diagrammatically, it will beV noted that the saidmechanism comprises the casing 21 within which is located a hollow floatmember' 29 operatively connected to a valve member 30, which valvemember cooperates with a seat 3 I. The construction is such that when apredetermined quantity of liquid refrigerant is present within thecasing 21, the float will lift the valve 30 from its seat and allowliquid refrigerant to ow at a reduced pressurethrough a conduit 32 tothe cooling unit or evaporator f1. Here because of 'its relatively lowpressure the liquid refrigerant boils and in so doing absorbs heat fromthe food compartment I4. The gaseous refrigerant is then drawn through aconduit I3 to the compressor where it is recompressed and the cyclerepeated. A motor driven fan 34 may be provided to force air over thecondenser coils 25 and thus assist in removing heat from the compressedrefrigerant.

Preferably, the base of the compressor unit is provided with a pluralityof flanges 25 having openings through which project bolts 2B, andsprings 31 are located around these bolts between each flange and thebase l5 whereby to resilient# ly support the encased motor-compressorunit.

An oil 'cooling coil 3l similar in construction to the condenser coil 2iis disposed beneath the condenser coil and in the path of air circulatedby the fan 34. This cooling coil is connected to the upper part of thecasing 23 by a conduit 39 .and to thelower part of the casing by aconduit 40,

for a purpose to be hereafter described.

Referring to Figure 2 wherein is shown in more detailed form thecompressor and motor operatively assembled, 4I designates generally abase of relatively heavy material upon which are supported thecompressor and its driving motor together with the surrounding casing23. The casing 23 may be sealed to the base in any desired mannerrbut ishere shown as provided with a strap 23a welded thereto and in whichstrap are provided at spaced intervals a plurality of loops 2lb throughwhich bolts 23e may be inserted and screwed into the base 4I so as tomaintain the casing 23'in fluid tight contact with the base 4 i, agrooved flange 4|a. being provided in the upper surface of the base 4Ifor receiving the lower edge' of the casing 23. The base 4I issubstantially circular and the compressor shaft 42 extends verticallyupward substantially at the center ofthe base. The lower end of theshaft runs 'on a thrust bearing 43 extending into a recess 44 formed inthe base. The base is alsoprovlded with a recess 4l for receiving aplate 4i upon which plate rests the compressor cylinder 41. The oppositeside of the compressor serves as a support for a substantially U-shapedmember 4I which in turn supports the motor stator 4I. When these partsare assembled, the compressor cylinder 41. is rigidly fastened betweenthe members 48 and 4l by means of bolts 5l, which in turn secure thewhole assemblyto the-base".

The lower member or plate 4l is provided with a recess 5I which receivesa bearing 52 formed on the lower end of the shaft 42, and the upper orU-shaped member 4l has formed therein, at its central part, a somewhatelongated recess 53 which serves as a surface for an upper bearing 54also formed integrally with the compressor shaft. 'I'he portion $5 ofthe shaft extending upwardly from the second main bearing is somewhatreduced in diameter and has keyed thereto the rotor 56 of the motor 2l.The extreme upper end of the shaft is screw-threaded as indicated at 51and a nut 58 engages the threaded portion to securely-clamp the rotor 56between nut 58 and a shoulder 59 formed above the upper bearing 54.

Immediately below the recess 45, formed in the base 4i for receiving theplate 46, there is a smaller recess 60 within which is located acentrifugal oil pump Si rigidly attached to and driven by the shaft 42.

Referring to Figures 4 and 8 wherein are shown details of the compressorconstruction, it will be noted that the piston $2 for the compressor iscircular in cross-section, and that it is eccentrically mounted on theshaft 42, through the intermediary of an eccentric member 6,3 formedintegrally with the shaft. A radial abutting member or blade 64 isrigidly attached to the piston O2 by means of bolts 64a, whereby thismember and the piston move as a unit. The radial member extends into acylindrical recess U5 between two substantially semi-cylindricaloscillating portions The nstruction is such that when the shaft 42 isrotated, the piston i2 wl nutate and thus its outer surface will alwayshave one point in contact with the wall of the cylinder, therebysqueezing any gas which may be ahead of the point of contact andcompressing the same until it is discharged through the valve 01.

As the radial member or blade 64 is rigidly a'ttached to the peripheryof the piston it will reciprocate between the semi-cylindrical membersI6 and these members will in turn oscillate in the cylinder l5. It willbe noted that the cylinder 6l is provided with narrow recesses 68 atdiametrically opposite points so that there is a relatively smallcontact'surface between each of the semicylindrical members I and theremaining portion of the cylinder wall Si. By this construction I havenot only reduced the bearing surface and consequent frictional loss buthave also provided a means for eifeotually reducing any tendency on thepart of the members to bindin the cylinder wall during the operation ofthe compressor.

The blade 64 serves as a constant partition be tween the high and lowpressure sides of the compressor and eifectually prevents the escape ofgas from one side to the other.

'Ihe intake valve 1B comprises a disc of spring steel 1I, firmlymaintained seated by thev force of a spring 12 which surrounds a pin 1Irigidly fastened in the cylinder wall. The discharge or exhaust valvecomprises a recess 14 formed in the upper member 4l and provided with acover member 15 from which a relatively short conduit liaextendsvertically upward. This conduit should, however, be long enough toextend at all times above the highest oil level obtainable with; in thecasing 2l. The valve mechanism proper consists of an elongated seatmember Il shown in Figure 12 and .provided with a downwardly dependinghollow cylindrical portion projecting into the discharge port 11 in atight. relation. 0n its upper surface this member is provided with arelatively narrow upwardly projecting seat 1I .nommantmitnimmt...raamt.t

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and is then cut away as indicated at 19 to provide a groove forreceiving a small quantity of oil which assists in quieting the actionof the valve. The valve member which cooperates with the seat 18comprises a flat leaf spring 88 shown in Figure 10. It will be notedfrom this figure that the portion of the spring engaging the valve seatis substantially circular in form and that from the circular portion asomewhat narrow neck extends to an enlarged portion 8|. In Figure 13there is shown a second leaf spring member 82 substantially rectangularin contour and provided at its outer end with an opening 82a for apurpose to be hereafter described.

Referring to Figure 9, it will be noted that the valve member 88 ismounted directly on the valve -seat, that the member 82 is superposedthereon in a slightly spaced relation, and is so maintained by aninterposed washer 83, and that a rigid Z-shaped member 84, is superposedon the member 82 with a portion 85 overhanging the valve seat and spacedsome distance therefrom. A

stud 86 is rigidly fastened to the underside of L sure be exerted on thevalve member 88 such as might be caused by the passage of a slug of oil,the4 construction is such that the member 8|), the spring 86 and thespring member 82 will all yield and allow the pressure to be relieved.

The lubrication of the moving parts of the motor and the compressor isaccomplished by a. forced lubrication system in which the circulation ofoil is maintained by the pump 6|. As has been previously stated thispump is located in a recess 68 formed in the lowermost portion of thecasing 4| and is directly attached to and driven by the main compressorshaft 42. The oil -pump may be of any desired construction but as hereshown. is a conventional centrifugal pump. Under normal operatingconditions, the casing 23 contains a body of oil to a level indicatedapproximately by the line 88, Figure 2. Thus it will be noted that thecompressor mechanism is completely immersed in an oil bath and that thelevel of the oil terminates just below the lower part of the statorwindings. When the motor and consequently the oil pump is operated, a.considerable .portion of the oil circulates out through passage-way 89vand through the conduit 48 to the oil cooling coil 38, where itstemperature is materially reduced, and then returns through conduit 39to the upper part of the casing 28. As the cool oil comes into thecasing it is deflected from the stator windings by means of a shield 98rigidly attached to the stator and' flows down Vthrough the spacebetween the outer surface of the stator and the casing23 and in sodoing, absorbs a considerable portion of the heat generated in themotor.` The oil then returns to the main body where itabsorbs additionalheat from the compressor and is then re-circulated through the coolingcoil by the pump.

Another portion of the oil flows through filter 9|a and passage-way 9|,Figure 7, to the lower shaft bearing 52, and is then forced into thecompressor where it effectually seals the moving parts including thepiston 62, the partition member or blade 64 and the two rocker members66. It will be noted that, each of the at surfaces of the two rockermembers adjacent to the blade 64, is provided with a recess 92 forpermitting the introduction of loil between the plate and the rockers.Some of the oil also passes through ports 93 drilled through theeccentric 63 and from there passes to the upper surfaces of thecompressor and then through grooves 94 formed in shaft 42 so that theupper bearing 54 is effectively lubricated. 'I'he oil then passes outover the upper edge of the bearing and drops down to the main body ofoil the discharge valve and conduit 15a, will separate by gravity afterthey have passed through that conduit.

During the operation of the blade member 64 it is inevitable that aquantity of oil will constantly be trapped between the end of this bladeand the cylinder casing in the space 9]. In order to prevent thistrapped oil from exerting an increased pressure on the end of the bladeand consequently adding to the load on the compressor a port 98 isdrilled through the cylinder casing and connects the space 81 with themain body of i oil. This port is made of 4relatively small diameter sothat while oil may pass freely from the space 81 to the main reservoir4because of `the pumping effect of the blade 64, it will not readilyflow in the reverse direction that is from reservoir toward the blade.

In order to permit the motor to attain approximately its normaloperating speed before anyv load is imposed on it by the pumping actionof the compressor, I provided an unloading device indicated generally bythe numeral 99, and attached to the upper end ofthe compressor shaft.This device comprises a hollow cylindrical body |88 having a port |8| inone of its vertical end walls', and having an adjustable closure nut |82screw-threaded into the opposite wall. A piston |83 is somewhat looselymounted in the cylinder |88 and carries at its outer end a valve |84adapted to cooperate with the port |8|. A spring |85 is interposedbetween the wall carried port 8| and the piston |88, the arrangementbeing such that when the machine is at rest, the spring will unseat thevalve |84. The unloading device 99 is attached to the compressor shaftby means of a screw threaded boss |86. 'Ihis boss is provided with ahollow passageway |81 opening directly into a second hollow passageway|88 extending4 axially throughout the entire length of the compressorshaft 42.

A passage-way |89 is provided in the base 4| for the passage of lowpressure gas from the cooling unit to the compressor.

'I'his passage-way. opens into a chamber ||8 in which is located a.

extending through the compressor shaft. Thus when the compressor is atrest, and the unloader valve |04 is unseated, there is an equalizationof. the pressure between the interior of the casing 23 when the pressurecorresponds to that of the compressor discharge through the port Ill,passage-ways |01 and |08, passage-Way 98 and the suction side of thecompressor. When the motor is started it is necessary for it to attain aspeed suicient to cause seating of the valve member |04 through thecentrifugal force acting on the piston |03 and against the tension ofspring |05 before this by-pass is closed, and as a result the motor willoperate under a substantially no-load condition until it hassubstantially attained its normal operating speed. l

In Figure 14 I have shown one arrangement for carrying the lead-inconnections for the motor through the casing 23. The number of theseconnections will of course vary with the type of motor used. Theconnecting means here shown comprise a screw threaded bushing ||4 of aninsulating material such as phenolic condensation product, having anelectrical conductor i|5 passing axially through and maintained againstaxial movement in the bushing by means of a flange I6 securely embeddedin the insulating material,

In the operation of my device the liquid refrigerant in the evaporatoror cooling unit I1 being under low pressure, boils and absorbs heat fromthe food compartment I4. The gaseous refrigerant is then drawn throughconduit 33, passage-way |09, iilter passage-way ||2 and intake valve 'l0to the suction side of the compressor. Here the gas is compressed by therolling motion of the piston 62 against the cylinder wall, this motionbeing in a clock-wise direction as shown in Figure 8. As the volume ofthe gas is reduced its pressure is increased and it nally passes outthrough the passage-way 11, discharge valve 80, chamber 14 and conduit15a to the interior of the casing 23. compressed gas passes through theconduit 24 to the condenser coil 25 where it is cooled and liquefiedbythe air current created by fan 3l. The liquefied as then passes tothefloat valve assembly 21 from which place the liquid re From this casingthe frigerant is delivered at a reduced pressure through the conduit 32back to the cooling unit I1. In the meantime, as has been previouslyexplained in detail, a portion of the hot lubricating medium passes outthrough conduit Il, through the cooling coil 38 where a substantialportion of its heat is removed, and back through conduit 39 to the upperpart of the casing 23. It is then deflected over the outer portion ofthe stator windings absorbing heat therefrom and then returns to themain oil reservoir where it absorbs further heat before beingre-circulated outside the casingby the oil pump 6|. Thus it will be seenthat I have provided a unitary cornpact refrigerating system employing acompressor of the rotary pendulum type in which the parts are socorrelated as to produce a maximum eiliciency and simplicity ofoperation and which may be quickly and rapidly assembled ordisassembled.

The lubricating system is both thorough and positive in its action, andin addition, the lubrieating medium is used as a means to assist inremoving the heat of compression outside the enclosed casing.

My unloading device as shown and described because of its simpleconstruction, has proved to be very effective and positive in itsaction.

While I have shown and described a specific embodiment of my invention,it will be understood that other forms might be adapted by coming withinthe scope of the appended claim.

I claim:

A compressing system comprising a base, a compressor, a motor mountedthereon, a casing enclosing said compressor and motor secured to saidbase, a body of lubricant disposed in said casing, and adapted tofunction as a lubricant sealing means and cooling agent, and means forpumping and conducting said lubricant outside of said casing for coolingsaid lubricant and then conducting said lubricant to the upper portionof the region in said casing where a portion of said cooled lubricant isdirected over the motor windings and the remainder of said lubricantvalong the inside surface of said casing.

FREDERICK R. ERBACH.

